1. Field of the Invention
The present invention relates generally to electric lamps and, more particularly, to electric lamps that are portable.
2. Description of the Prior Art
Portable illumination devices are very useful and come in wide variety of shapes and sizes. Most portable illumination devices are powered by electric current, either centrally distributed AC power or DC batteries. There are, however, portable illumination devices that are powered by combustion of a liquid fuel. One such combustion-powered portable illumination device is an oil lantern.
The oil lantern has a number of desirable features. It has a relatively long, vertically oriented globe which provides an especially utilitarian as well as aesthetic function. The oil lantern has quite a bit of its weight relatively close to its base providing it with a low center of gravity which provides substantial stability against being tipped over. The oil lantern also has a wire carrying handle that is located at the top of the lamp. This location of the handle permits a good grasp. In addition, the wire permits a person to wrap one's hand around the wire and form a tight grip. The wire handle also permits the lamp to be hung by its handle.
Aside from its desirable features, the oil lantern has a number of disadvantages. The fuel is unpleasantly odorous and breathing fuel vapors may be unhealthy. If the fuel leaks, a substantial fire hazard can be created. Fuel must be periodically replenished. The oil lantern generates quite a bit of heat as well as light, and the heat may be undesirable in certain weather conditions, such as hot summer days. To start the oil lantern, one must have a source of ignition such as a match. Often a match is not readily available. Moreover, in a dark room a person may need two hands to partially disassembly the oil lantern in order to light it. It may be difficult for the person to use two hands in a dark room when one hand may be needed to carry a lighted match.
Although the oil lantern has both desirable features and disadvantages, for most people the disadvantages outweigh the desirable features, and use of oil lanterns is quite limited. In this respect, it would be desirable if a portable illumination device were provided which has the desirable features of an oil lantern but does not have the disadvantages associated with the oil lantern.
Many of the desirable features of the oil lantern can be obtained by an electrically powered portable illumination device. More specifically, it would be desirable if an electrically-powered portable illumination device were provided which has a relatively long, vertically oriented globe which provides a utilitarian as well as an aesthetic function. It would also be desirable if an electrically-powered portable illumination device were provided which has quite a bit of its weight relatively close to its base providing it with a low center of gravity which provides substantial stability against being tipped over. In addition, it would be desirable if an electrically-powered portable illumination device had a wire carrying handle that is located at the top of the lamp.
In addition, many of the disadvantages of the oil lantern can be eliminated by employing an electrically-powered portable illumination device. More specifically, the use of an electrically-powered portable illumination device precludes the presence of a liquid fuel that is unpleasantly odorous and gives off vapors that may be unhealthy to breath. An electrically-powered portable illumination device precludes fuel leaks and eliminates a fire hazard that can result from a fuel leak. In addition, an electrically-powered portable illumination device does not present a problem of incomplete fuel combustion, does not require replenishment of a liquid fuel, does not require a match to start, and does not require two free hands to start the lantern illuminating.
Throughout the years, a number of innovations have been developed relating to electrically-powered portable illumination devices, and the following U.S. patents are representative of some of those innovations: U.S. Pat. No. 3,456,102; 3,767,911; 4,286,310; 4,562,521; and U.S. Pat. Des. No. 311,592.
More specifically, U.S. Pat. No. 3,456,102 discloses a portable electric hand lantern that includes a reflector for directing the light in a monodirectional beam. Often a light source is desired that provides illumination in a 360 degree circle, not is a monodirectional beam. In this respect, it would be desirable if a portable illumination device provided illumination in a 360 degree circle.
U.S. Pat. No. 3,767,911 discloses a battery-powered electric lantern which includes a centrally disposed rod that serves as a support and backbone for a battery case, a lens, and a plurality of lamps. A plurality of lamps are arrayed circumferentially around the centrally located support rod. The support rod, aside from providing its support function, also serves as an electrical conductor in the electric circuit. A disadvantage is imposed by the centrally disposed support rod. It prevents a source of illumination from being disposed in a central location in the lamp. The centrally located disposition of the support rod requires that the sources of illumination be arrayed circumferentially around the support rod. The visual effects of circumferentially arrayed lamps versus the visual effects of a centrally located lamp are quite different. In this respect, it would be desirable if an electrically-powered portable illumination device were provided which includes a centrally disposed source of illumination.
Moreover, the centrally disposed support rod in U.S. Pat. No. 3,767,911 serves as an electrical conductor in the lamp circuit. Such a dual role poses hidden dangers. It subjects the support rod to short circuits. Also, if the support rod becomes slightly bent, it may be prevented from providing electrical continuity in its circuit contacts. Thus, a lamp that undergoes slight structural damage may be completely disabled by being unable to provide circuit continuity for powering a lamp. In this respect, it would be desirable if an electrically-powered portable illumination device were provided which did not include a structural support rod that also serves as an electrical conductor in the lamp circuit.
U.S. Pat. No. 4,286,310 discloses a battery-powered lantern that includes a transparent upper light diffuser that is supported by a lower battery case. A handle or aperture for suspending the lamp from an overhead support is integrally formed with the light diffuser. As a result, when the lamp is suspended from an overhead support, the weight of the batteries and the battery case must be supported by the light diffuser. In this case, the light diffuser must serve two opposing functions: provide light diffusion; and provide structural support for the batteries and battery case. Preferably, it should not be necessary for a light diffuser to also serve as a structural support for the batteries and battery case. In this respect, it would be desirable if an electrically-powered portable illumination device were provided that included a light diffuser which does is not required to provide structural support for a battery and a battery case.
U. S. Pat. No. 4,562,521 discloses a conventional lamp stand that is adapted to receive a collapsible oriental lantern. U.S. Pat. Des. No. 311,592 is similar to U.S. Pat. No. 3,456,102 discussed above for its disclosure of an electrically-powered portable illumination device which includes a reflector for directing the light in a monodirectional beam.
Still other features would be desirable in a portable electric lantern apparatus. For example, an act,,ml fuel oil-powered lantern may provide a source of illumination that flickers as the flame flickers. Such a flickering light source may be pleasing to some persons, and it would be desirable if an electrically powered portable illumination device had a flickering light source.
Thus, while the foregoing body of prior art indicates it to be well known to use an electrically-powered portable illumination device, the prior art described above does not teach or suggest a portable electric lantern apparatus which has the following combination of desirable features: (1) has the desirable features of a fuel-oil powered lantern but does not have the disadvantages associated with the oil lantern; (2) has a relatively long, vertically oriented, light diffuser which provides a utilitarian as well as an aesthetic function; (3) has quite a bit of its weight relatively close to its base providing it with a low center of gravity which provides substantial stability against being tipped over; (4) has a wire handle that is located above the lamp; (5) precludes the presence of a liquid fuel that is unpleasantly odorous and that gives off vapors that may be unhealthy to breath; (6) precludes fuel leaks and eliminates a fire hazard that can result from a fuel leak; (7) does not present a problem of incomplete fuel combustion, does not require replenishment of a liquid fuel, does not require a match to start, and does not require two free hands to start the lantern to illuminate; (8) provides illumination in a 360 degree circle; (9)includes a centrally disposed source of illumination; (10) does not include a structural support rod that also serves as an electrical conductor in the lamp circuit; (11) includes a light diffuser which is not required to provide structural support for a battery and a battery case; and (12) has a flickering light source. The foregoing desired characteristics are provided by the unique portable electric lantern apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.